1. Technical Field
The present invention relates to a discharge lamp driving device, a light source apparatus, a projector, and a discharge lamp driving method.
2. Related Art
A problem is known in which, if a lamp voltage is reduced due to deterioration in a discharge lamp, an electrode is unlikely to be melted, and thus a protrusion of an electrode tip is thinned so that deterioration in the discharge lamp is accelerated.
In relation to this problem, for example, as disclosed in JP-A-2011-23288, a method has been proposed in which a DC current is inserted into an AC current supplied to a discharge lamp, and a DC current component is increased according to the progress of a deterioration state of the discharge lamp.
However, in the above-described method, since a melting amount of a protrusion of an electrode tip serving as an anode is improved due to the DC current but the temperature of an electrode serving as a cathode is reduced, there is a problem in that a shape of an electrode tip serving as the cathode is deformed, and thus flickering occurs. Therefore, there is a case where the lifespan of the discharge lamp may not be sufficiently lengthened.